When most people think of plastic today, the first thought that comes to mind probably involves environmental concerns. Over the last many decades, we have seen the damage plastics cause to oceans and aquatic life. (Check out this deep dive–pun intended–into oceanic pollution in this Bold story!) We have also seen how recycling efforts have failed to keep pace with production. But scientists across the globe are investing a great deal of effort toward making advanced plastics for the future. Some are exploring ways to incentivize recycling efforts. Others are creating brand new super polymers that will likely change the world as we know it. In the process, our views of plastics may significantly change in the coming years.
At the current time, problems associated with plastics involve two key areas. The first one, with which we are quite familiar, relates to its recycling. Though many plastics can be recycled, there is little money in it to encourage these activities. Secondly, existing plastics remain difficult to work with, requiring additional efforts to mold the material into desired objects. But this looks to be rapidly changing in this age of advanced plastics. New processes related to old plastics and the discovery of super polymers introduce new opportunities. Both look to be ushering in a new era where plastics may once again enjoy a favored position.
“Our approach views plastic waste as a potentially valuable resource for the production of new molecules and materials. We hope this method could drive an economic incentive to recycle plastic, literally turning trash into treasure.” – Frank Leibfarth, Assistant Professor of Chemistry, UNC College of Arts & Sciences
Advanced Plastics to Address Recycling Problems
When it comes to plastics, the U.S. has a major environmental problem. Each year, over 46 million tons of plastics are produced in the country. This equates to about 287 pounds per person annually. These figures alone might not be such a big issue if plastics were routinely recycled. However, the average rate of plastic recycling that occurs in the U.S. is about 9 percent. In other words, production far outpaces reproduction, and this is what is causing notable environmental impacts. Because recycling plastics is costly and of limited production value, incentives are lacking. This is one area of sustainable practices, however, that researchers hope to change.
Currently, chemists at the University of North Carolina at Chapel Hill are working with advanced plastics to address this issue. Existing plastic polymers and super polymers are extremely strong and resistant to reuse. The reason for this is because of the existing hydrogen bonds within these structures. Previously, recycling plastics was limited because breaking these hydrogen bonds was cost-ineffective. Therefore, efforts to reuse plastics was hindered by a lack of incentives. But UNC researchers have discovered a reagent that can readily (and inexpensively) break these hydrogen bonds. In turn, this would make it much easier to recycle existing plastics. By stripping them of their hydrogen molecules, they can then be reused for all types of new applications.
“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things. It has very unusual properties and we’re very excited about that.” – Michael Strano, Professor of Chemical Engineering, MIT
Introducing Super Polymers
While it’s important to address plastics recycling, other researchers are focused on other areas of advanced plastics. In new MIT research, chemical engineers have developed super polymers that will likely revolutionize materials for the future. Traditionally, plastics are created in monomer structures that consist of one-dimensional linear chains of molecules. These chains are then molded into the shape of various objects through a process that takes time and effort. However, MIT researchers have now developed super polymers that exist in two-dimensional sheets. Plus, these advanced plastics self-assemble, requiring no effort at all in production.
The ability of these super polymers to form two-dimensional sheets is quite a big deal. The material is 6 times more resistant to breaking than bulletproof glass. It is also twice as strong as steel despite being a sixth of its density. Also, its lattice structure is impermeable to both gases and liquids, making it an ideal material for protecting underlying structures. As a result, these super polymers can be used as lightweight, incredibly durable materials that could revolutionize a number of industries. This not only includes those involved in producing smart phones and devices but likewise construction and automotive industries as well.
“An important aspect of these new polymers is that they are readily processable in solution, which will facilitate numerous new applications where high strength to weight ratio is important, such as new composite or diffusion barrier materials.” – Matthew Tirrell, Dean of the Pritzker School of Molecular Engineering, University of Chicago
The Future of Advanced Plastics
The discovery of these super polymers is certainly an exciting development. In addition to the new potential applications of these advanced plastics, they also can be developed faster and less expensively. The structure of these two-dimensional molecules also has an auto-catalytic tendency. This means that once they begin to form, the structure encourages the addition of increasing layers of these super polymers. In essence, all that is required is the addition of these special plastic monomers to a water solution. Hydrogen bonding then does the rest, creating the ”stacked disc-like” super polymers.
The future potential of these advanced plastics is tremendous. Some industries have already been mentioned, but these super polymers could be quite beneficial for the space economy. (Catch up on the advances of the “Space Economy” in this Bold story.) Incredibly strong and lightweight materials are routinely sought for all sorts of space equipment. Plus, its impermeability could offer the high-quality protection these same materials may require. Likewise, combining these advanced plastics with better recycling techniques could help resolve their environmental impact. Based on these recent discoveries, ti certainly appears we will be seeing plastics of the future in a different light.